Art of refining



July 14, 1942. E. J. MARTIN ART OF REFINING Filed May 15, 1940 s Y E N nA Patented July 14, 1942 .Y umorismo Edward J.' Martin, am chimio, ind.,assignmto Sinclair Refining Company, New York. N. Y., a corporation ofMaine u A upnwun May 1s, 19in, semi No. asesor s claims. (ci. 2oz-56)"This invention relates broadly to the treatment of mineral oil to removecontaminating coloring matter therefrom andl more -particularly to aneconomic treatment ofthe blend oi' `naphtha and color solvent used inthereactivation of decolorizlng earth for recovery of the color solvent andnaphtha. Y 4 j. In the treatment ofmineral oil with decolorizing earth,contaminating coloring matter is. re-

moved from the-oiland adsorbed bythe earth.- l After separationL of thetreated oil and earth, v the earth isv usually 'washed-with naphtha tore- Vemployed in the make-up of additional color solvent-naphtha blendand the upper layer-treated by distillation to' separatethecontaminating coloring matter and tovrecoveradditional color solventand naphtha.`

m the treatment of minerai dus .with decoior- 'izlng earth'a'iinalnaphtha. wash isnecessaryfor economic operationtorecover the smallamount of color solvent that. is-entrain'ed-in the reactimovesubstantially all o'f the oil and the deoiled `earth may be then.treated with a blend of nephtha and a color solvent to removeadsorbedcoloring matter Afrom the earth and reactivate it for Iurtheruse. s nVarious color solvents have been proposed for `use inV reactivatingspent clays used in the treatment of mineral oil. Amongthe solventswhich have' been*v used are vethyl alcohol and methyl ethylketone'.yMany of .these solvents as sold `commercially are not completelymiscible with naphtha..L If the `blend of solvent and naphthaispermitted to stand, it will separate into two liquid phases and thetars and other coloring matter. removed from the treated earth areretained inthe upper layer which is rich invnaphy tha. yIthereforepropose to y'separate the color solventblend, by decanting, toobtain a lower layer rich in alcohol or other color solvent andsubstantially free from tar or other coloring mat-- ter which can beemployed in the make-up of additional solvent blend. The upper layer,which is rich in nphtha and contains the contaminating coloring matterfrom the earth, may bedis- .tilledto recover additional alcohol andnaphtha y l and to separate the contaminating coloring matter from thealcohol andnaphtha. A

In carrying out my invention using commercial ethyl alcohol as the colorsolvent aslurry y in preparation .of l fresh naphtha-fcolor solvent`blend containing'three parts of naphtha and one vted clay. The '.nltrateso obtained -therefore contains a small amount oi.' color solvent "and aconsiderable quantity oVf-naphtha. 4Asolventrecovery, unitmusttherefore' be operated to yield a product containingupv to 5opercentalcohol to permit the recovered material to' be employed part ofcolor solvent.7 Due tothe formation of able tocoo'l the distillate to atemperature of of deoiled decolorizing earth and a blend ofsubstantiallyone part of ethyl valcohol and three l l parts of naphthais prepared and the blend separated from they earth in a nlter to removethe contaminating coloring matter that has been ad- `sorbed from the oilby the earth. The iilter cake is then washed with naphtha to remove anyremaining traces of color. solvent and is ready for reuse. The colorsolvent-naphtha blend andthe nahths usedv in washing the earth iscouected in av tank and permitted to separate into two liquid phases. 'I'he lower layer which is rich in alcohol and substantially free fromcontaminating coloring matter may then be withdrawn'and `rich upperlayer is constant boilingmixturesbelow this concentration a singlepassthrougha distillation unit will not `yield the desiredalcohol`ri`ch"cut. In carryiing out my invention I'- therefore ind itdesir- .approximately F. and collect thecondens'ate so formed in -atank. to permit fur-ther phase separation. The resultant alcohol rich:lower layeris then used with the alcohol rich lower layer separated in'the nrst phase separation prior to-distillationv in the preparationlof.4 additional color solvent-naphtha blend and thenaphtha tillation.the accompanying drawing -I have shown a grammaticview of apparatus`illustrating the process of the present invention.- 1

In the removal of contaminating colorlng'matter i'rom mineral oil theoil`may first oe "blended with a solventto reduce it to aviscosity at whichit can be readily handled and is then mixed with .a decoloiimg earth.' 4Many decolorizing earths may be employed 'for this purpose. Asexamplesof decolorizing earths now used I may mention nely divided fuliersearth. `activated bauxites.

such `as Poi-ocel, and acid treated bentonites.

such as Fitrol or"Tonsil. The synthetic adsorbent decolorizing earthknown as Magnesol which is a hydrated magnesiumsilicate, may also beemployed. It is understood that the term decolorizing earth" as used inthe description and claims of the present invention refers to any of thenaturally occurring or artiiicially prepared decolorizing materialsknown to the artk and used in bleaching mineral oils. 'i The oil andnaphtha blend is brought into contact with the decoloriez-4 ing earth,such as Magnesol. employing from 6 returned'to the still for dislbasisby weight ofoil, at temperatures of 150 F. to 600 F. and maintainedin contact with the decolorizing earth until substantially all of thecontaminating coloring matter is removed from the oil. The naphtha canthen be removed by distillation from themixture of cil and earth and thedecolorized oil separated from the decolorizv ing earth in anysuitablemanner, as by iiltering,

to 12 percent of thedecolorizing earth on a dry.

l The deoiled decolorizing earth is then ready for treatreturned to thetank 3. The top layer produced in this phase separation which consistsof over 90 percent naphtha is withdrawn through pipe -it is necessary torecover a product containing up to 50 percent color solvent from' thesolvent recovery unit in order to balance out in the preparation otcolor solvent-naphtha make-up containing three parts of naphtha to one'part of speciiic example of the process Lemploy a blend consisting of 1part oi commercial ethyl alcohol and 3 parts 'of'2IJ0-3Ii0` naphtha.This blend is contained in a'tank 3 and is delivered to the mixing tankthrough pipe l by means of a pump 5. The mixing tank may be providedwith suitable heating meansf (not shown) whereby the slurry ofdecolorizing earth and color solvent-naphtha blend is heated to atemperature of about 130 F. 'I'he slurry is then delivered through apipe 6 to a vacuum iilter 1 by means of a pump 8 and the colorsolvent-naphtha blend together with the tars and other contaimnatingcoloring mattei' is separated from the decolorizing earth and deliveredthrough a pipe 9 to a tank or receiver 9. The decolorizing earth is thengiven a iinal naphtha. wash toremove any entrained color solvent,thenaphtha being delivered from a tank I0, through pipe II `to the filter1, -a pump I2 being provided in the line for this purpose. In practice Iemploy about .8 gal. of naphthaper pound of clay in the `iinal naphthawash. The filtrate consisting of a small amount of alcohol and aconsiderable quantity of naphtha is also delivered through pipe 9' totank or receiver 9. 'lne iilter cake is removedirom the illter by a.scraper blade I3 and delivered by suitable conveying means Il for reusein the treatment of oil.

The color solvent-naphtha blend containing tar'sand other contaminatingcoloring matter is then allowed to standin the tank 9 until phaseseparation occurs and a lower layer which is substantially free ofcontaminating Acoloring matter is withdrawn from the tank 8 through pipeI5 and returned to the tank 3 for use in make-up of additional colorsolvent-naphtha blend. A

. pump I8 is arranged in the line I5 for this purpose. This bottom layerwhich comprises 8 to l0 percent of thetotal quantity contains aboutthree parts of color solvent to one-part of naphtha. The upper. layer,which is rich in naphtha and which contains substantially all of thecontaminating coloring matter removed from the decolorizing earth, iswithdrawn from the tank 8 through pipe I1 and delivered to a pipe stillI8. A suitable pump I8 is arranged in theline I1. Thewapors produced inthe still I8 are delivered to -an atmospheric iractionating tower 28through pipe 2|. The vapors from tower 20 pass out at the top throughpipe 22l through a heat exchanger 23 where they are cooled to atemperature of substantially '90 F. causing them to condense and arethen collected in a tank 24.

The condensate collected in tank 2l is also Dcrcolor solvent. Bycontrolling the proportion of the naphtha rich upper layer which isrecycled from tank fthe proportion oi.' alcohol or other color solventrecovered may be controlled'to yield the proper proportion of alcohol inthe liquid returned to the tank 3.

The bottoms from atmospheric tower 20, containing substantially all ofthe tars and other contaminating coloring matter is delivered throughpipe 30 to a vacuum tower 3l and the tar bottoms are removed from thebottom of this tower through a pipe 32 by pump 33. The vapors from thevacuum tower pass through pipe 34 to a cooling device 35 and thecondensate is collected in a tank 36. lUncondensed gases and vapors exitfrom this tank through pipe 31 and the condensate which is substantiallyall naphtha is removed from the tank through a pipe 38. A pump 39'isarranged in this pipe and the other end of the pipe is connected to tankIII in which the naphtha is stored for the nal naphtha wash in thefilter 1. l

While the process has been described particularly with respect to theuse of commercial ethyl alcohol, it may be employed in connection withany of.l the well-known color solvents used vin treating decolorizingearth which are partially miscible with naphtha in blendsofsubstantially three parts of naphtha to one part Nof color solvent. Theinvention may thus be applied to blends or naphtha and ketonescontaining more than 5 percent of water and to blends of naphtha andmethyl alcohol.- The phase separation of the filtrate in tank 8 permitsa recovery ot from B to 10 percent of the liquid used in thereactivating of the decolorizing earth and the final wash of thedecolorizing earth which is substantially free from contaminatingcoloring matter and which contains about three parts of alcohol and onepart of naphtha. The phase separation in tank 24 together with recyclingof part or all of the upper layer removed from this tank permits controlof the amount of alcohol, or other color solvent, return to the tank 3to give the proper proportions of alcohol and naphtha in the blend usedfor preparing the color solvent-naphtha blend and additional naphtharecovered from the vacuum tower 3| is reused as the nal naphtha wash.

ing earth containing contaminating coloring mitted to stand until aphase separation occurs matter and the contaminating coloring matterremoved from the earth.' permitting the collected liquid to settle intoa lower layer rich in the material from the group consisting of ketonesand ethyl alcohol and substantially free from contaminating coloringmatter and an upper layer rich in naphtha and containing substantiallyprises collecting a blend or naphtha and methyl ethyl ketone used inreactivation of-decolorizing e earth containing contaminating coloringmatter terial from the group consisting of ketones and ethyl alcohol.used in reactivation of decolorizing earth containing contaminatingcoloring matter and the contaminating coloring matter removed from theearth, permitting the collectl ed liquid to settle into a lower layerrich in the material from the group consisting of ketones and ethylalcohol and substantially free from contaminating coloring matter and anupper layer rich in naphtha'and containing substantially all thecontaminating coloring matter removed from the earth, withdrawing thelower layer and distilling the upper layer to separate the contaminatingcoloring. matter from the naphtha and material from the group consistingof ketones and y.ethyl alcohol.

3. The herein described process which comprises collecting a blend ornaphtha and a material from the group consisting of ketones and ethyl`alcohol used in reactivation of decolorizing earth containingcontaminatingcoloring matter and the contaminating coloring matterremoved from the earth, permitting the collected liquid to settle into alower layer rich in the material from the group lconsisting of ketonesand ethyl alcohol and substantially free from contaminating coloringmatter and an upper layer rich .in naphtha and containing substantiallyall the contaminating coloring matter removed lfrom the earth,withdrawing the lower layer, dis- 4. The herein described process whichcom- 50 and the contaminating coloring matter removed from the earth,permitting .it to settle in a lower layer :ich in methyl ethyl ketoneand substantially free from contaminating coloring matter and an upperlayer rich in naphtha and containing substantially all the contaminatingcoloringk matter removed from the decolorizing earth, withdrawing 'thelower layer, and treating the upper layer to separate the contaminatingcoloring matter therefrom and to recover additional naphtha and methylethyl ketone.

5. The herein described process which vcomprises collecting a blend ofnaphtha and methyl ethyl ketone used in reactivation of decolorizingearth containing contaminating coloring matter and the contaminatingcoloring matter removed i'rom the earth, permitting it to settle in alower.

layer rich in methyl ethyl ketone and substantially free fromcontaminating coloring matter and anupper layer rich in naphtha andcontaining substantially all the contaminating coloring matter removedfrom the decolorizing earth, withdrawing the lower layer. and distillingthe upper layer to separate contaminating coloring matter fromvthenaphtha and methyl ethyl ketone.

6.,The herein described process which comprises collecting a blend ofnaphtha and methyl l ethyl ketone used in reactivation of decolorizingearth containing contaminating coloring matter and the contaminatingcoloring matter removed from the earth, permitting it to settle in alower layer rich in methyl ethyl ketone and substantially freeV fromcontaminating coloring matter and an upper layer rich in naphtha andcontaining substantially all the contaminating coloring matter removedfrom the decolorizing earth, withdrawing thelower layer, distilling theupper layer, lractionating the distillate to separate a portion ofnaphtha and. contaminating coloring matter as liquid and the remainingnaphtha and methyl ethyl ketone as vapor, cooling the vapors to condensethem, collecting the condensate, and permitting it to settle into alower layer rich in methyl ethyl ketone anduan upper layer rich innaphtha.

EDWARD J. MARTIN. y

